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Here we have graphs on a dyno dynamics of the Stage 2 tune from CA Automotive. This Dyno is obviously set to read high as they are not making 538 whp, impossible. The dyno is corrected but we have no idea just how high the correction factor is. The gains are claimed on 93 octane but we just don't find these numbers possible without huge correction factors to exaggerate the gains on what is a notoriously low reading dyno.

Before dyno:

After:

CA automotive says there are no tricks or exagerrated correction factors here, but clearly, that is exactly what they are doing:

Here is what a modified M5 really looks like on a dyno dynamics, this one with aftermarket exhaust:

these are not RWHP they are crank HP plots taken from an independant dyno. However, i think this is a plot from their stage 2 package - pulley, scoops cat back and remap.....if it is then, I can confirm it is much quicker than stock. THere are another couple of cars that have had stage 2 remap, and their dyno plots look good. several UK people are having their cars remapped in the coming weeks and perhaps they will be good enough to post their results.

these are not RWHP they are crank HP plots taken from an independant dyno. However, i think this is a plot from their stage 2 package - pulley, scoops cat back and remap.....if it is then, I can confirm it is much quicker than stock. THere are another couple of cars that have had stage 2 remap, and their dyno plots look good. several UK people are having their cars remapped in the coming weeks and perhaps they will be good enough to post their results.

Crank hp? So then this dyno dynamics is corrected heavily then, and that exaggerates the gains, does it not?

Going only by the 1st dyno sheet its either reading low crank power, or very high wheel power stock. Just by the lack of accuracy in the 1st dyno there is no reason to go onto the next dyno sheet. Until there are a few different before and after independent dynos authenticating the effectiveness in a tune we should not get too worked up by a random dyno sheet.

Going only by the 1st dyno sheet its either reading low crank power, or very high wheel power stock. Just by the lack of accuracy in the 1st dyno there is no reason to go onto the next dyno sheet. Until there are a few different before and after independent dynos authenticating the effectiveness in a tune we should not get too worked up by a random dyno sheet.

EXACTLY, but for some reason M5board members eat this $#@! up like it is gospel.

Our dyno results show bhp at the Engine, NOT at the wheels, hence the confusion; once you take this into account the figures stack up correctly.

Whilst 476 bhp is a little on the low side for stock crank output, it is not uncommon. What matters is the gain.

To re confirm, we have used an independant dyno, and the figures have not been messed with in any way.

We are happy to carry out this work at any independant dyno a customer may wish, thereby eliminating any doubts at all :-)

many thanks

I still have question if you please.

So this was an independent chasis dyno that was taken in by a customer or that CA Automotive took in on behalf of a customer?
What drivetrain loss did the dyno use to compute the crank power?
Why is the torque so low, below stock even after the tune(370 tuned vs 384 stock)?

Our dyno results show bhp at the Engine, NOT at the wheels, hence the confusion; once you take this into account the figures stack up correctly.

Whilst 476 bhp is a little on the low side for stock crank output, it is not uncommon. What matters is the gain.

To re confirm, we have used an independant dyno, and the figures have not been messed with in any way.

We are happy to carry out this work at any independant dyno a customer may wish, thereby eliminating any doubts at all :-)

many thanks

You claimed in your original post that no corrections were used. However, by using BHP the dyno dynamics was heavily corrected. Perhaps in the future posting the correction factor would show far more accurate results in comparison to other tuners?

The reason being, crank dynos exaggerate the gains making it appear that you gain more HP. Which I am sure you know, which is why the dyno was heavily corrected to BHP to begin with. A way to avoid reading low for crank would be to simply run it at the wheels, or, in shootout mode to prevent any messing with correction factors.

What matters is the gain just as you stated, but giving the complete picture is also important if the procedure is to be taken as valid. Allowing customers to dyno your software independently is a nice gesture and the right step to alleviate any doubt.

You claimed in your original post that no corrections were used. However, by using BHP the dyno dynamics was heavily corrected. Perhaps in the future posting the correction factor would show far more accurate results in comparison to other tuners?

The reason being, crank dynos exaggerate the gains making it appear that you gain more HP. Which I am sure you know, which is why the dyno was heavily corrected to BHP to begin with. A way to avoid reading low for crank would be to simply run it at the wheels, or, in shootout mode to prevent any messing with correction factors.

What matters is the gain just as you stated, but giving the complete picture is also important if the procedure is to be taken as valid. Allowing customers to dyno your software independently is a nice gesture and the right step to alleviate any doubt.

Sticky,

On a dyno dynamics machine there is no correction factor going from wheel to crank figures but rather a outright simple multiplier based on the shootout mode chosen.
So, if a car makes say 400 wheel horsepower and the shoot out mode of shoot8 (used on 8 cyl or above engine) is used then the dyno simply uses a factor of 1.2 (20%) which is added to the wheel horsepower accross the entire recorded rpm band.

Correction factor is something entirely different.
Correction factors are applied to the wheel horsepower figures first and then the shootout mode transmission loss factor is added to that.

Typically correction factors hover from around 0.98-1.02% and these are calculated from barometric pressure, relative humidity and air temperature.

One very good thing about shootout mode is that is fixes the ramp rate and all but one correction factor is then locked which is inlet air temperature.
It also displays the conditions which make up the correction factor on every graph.

From what I can see of many of the graphs generated in the US is that no one shows the variables which make up the correction factor and you cannot determine if the car was run with the same ramp rate on a before/after comparison test. I am not implying that foul play is occuring but you just have no idea at all of what's going on.

So, it doesn't matter if you look at wheel or crank figures. The correction factors are applied to both and the only different between the two are the conversion factor.

I can show examples of this.

I get the feeling the people are under the assumption that wheel figures are completely raw and have no correction factors applied to them. Correct me if I am wrong.

On a dyno dynamics machine there is no correction factor going from wheel to crank figures but rather a outright simple multiplier based on the shootout mode chosen.

Absolutely correct, but the point is to read like BHP it has to a heavier correction factor. This was left out of the original post which stating correction factors were not used to prop up the figures. Clearly, everyone involved is now admitting they were. The multiplier itself is the correction factor we are talking about here.

Originally Posted by evolve

One very good thing about shootout mode is that is fixes the ramp rate and all but one correction factor is then locked which is inlet air temperature.
It also displays the conditions which make up the correction factor on every graph.

Exactly, so why was it not used?

Originally Posted by evolve

I get the feeling the people are under the assumption that wheel figures are completely raw and have no correction factors applied to them. Correct me if I am wrong.

No, not at all. The main thing is, when people see dynos, they are expecting wheel hp numbers. So with the multiplier used here it makes it seem as if the software is putting out much more HP than the competition which it isn't. The average person won't even understand this and simply look at the peak numbers. I think this is why it was done. Multipliers on the dyno dynamics are used for the lower wheel figures as well. Frankly, I would like to see everyone using a dyno dynamics disclose their multiplier (correction factor) used or utilize shootout mode which will keep the numbers in the same frame of reference for all operators. I believe this is why the company included the feature in the first place.

Whilst 476 bhp is a little on the low side for stock crank output, it is not uncommon. What matters is the gain.

I saw this then I saw Sticky refer to it again and I would like to throw my 2 cents in. The more important factor is the final numbers not the gain!
The gain is only the difference between stock and tuned. But many people forget there is a difference in the stock tune unit to unit. Not all 2010 m5 will dyno the same. If a tuner just happens to tune an m5 that dynos low, does it mean they can get that same difference out of all there tunes? In this case can CA Auto get 60 bhp out of a m5 that dynos 510bhp stock? I believe they would be able to get another 30 out of it not 60.

We saw this a lot with the gt500. Some stock gt500 dyno at 440 rwhp(DJ). Other stock gt500 dyno at 480rwhp(DJ) However after tuning(regardless of tuner) their rear wheel horsepower were all around 520.
Tuner A: 440 to 520 ~ 80hp difference
Tuner B: 480 to 520 ~ 40hp difference

In the example with the GT500's one tuner is not better than the other in terms of power, the only difference is the point at which they started.

I saw this then I saw Sticky refer to it again and I would like to throw my 2 cents in. The more important factor is the final numbers not the gain!
The gain is only the difference between stock and tuned. But many people forget there is a difference in the stock tune unit to unit. Not all 2010 m5 will dyno the same. If a tuner just happens to tune an m5 that dynos low, does it mean they can get that same difference out of all there tunes? In this case can CA Auto get 60 bhp out of a m5 that dynos 510bhp stock? I believe they would be able to get another 30 out of it not 60.

A combination of factors matters, but we need to see the delta and the end result. I see what you are saying, you can gain more on a car that put out less to begin with, that can certainly happen. If so, tuners might be encouraged to seek out cars that are "weaker" to begin with.

Originally Posted by Ca Automotive

no tricks, exaggerated correction factors or other funny business :-)

Clearly, an exaggerated multiplier was used since we are being told to look at this form a BHP perspective. I'm not doubting they are getting gains, but this is the exact reason we prefer showing the gains to the wheels and honestly, a dynojet just simplifies things. Dyno dynamics are great dynos but we see so much multiplier manipulation that it is just ridiculous. This may not even be their fault, whomever runs this dyno may run a large multiplier. Either way, independent results are always appreciated to substantiate.

I will put some work into allowing people to understand dyno read outs a little more.

What is certain is that there is absolutely no standardisation especially in the US. In the UK atleast we all use flywheel calculation and all use the same gears and shoot out mode. The only variable then becomes the operator and how he straps the car between runs. This is easily caught out.

Will be back later and will correspond with Sticky and get something written up.